I faced the same issue using bzr 2.5 (currently on precise, using ubuntu default package). I downloaded the latest version possible of bzr (branching the trunk, rev.6553, bzr 2.6.0dev3), and _find_ancestors seem to be already implemented in bzrlib/btree_index.py (as Wouter's branch kinda does). Using the fresh version of bzr, I wasn't able to reproduce the issue. Should we consider this bug fixed in bzr upstream?
I faced the same issue using bzr 2.5 (currently on precise, using ubuntu default package). I downloaded the latest version possible of bzr (branching the trunk, rev.6553, bzr 2.6.0dev3), and _find_ancestors seem to be already implemented in bzrlib/ btree_index. py (as Wouter's branch kinda does). Using the fresh version of bzr, I wasn't able to reproduce the issue. Should we consider this bug fixed in bzr upstream?